Multipolar circuit-protection assembly for a collector rail system

ABSTRACT

The invention relates to a multipole fused switch arrangement for busbar systems having at least two fused switch units ( 10 ) which each holds a fuse link ( 20 ), with the fused switch units ( 10 ) having a mounting and contact apparatus ( 11 ) for a busbar, and having a switching apparatus for closing and interrupting the circuit of all the switched fuse units, with the fused switch arrangement comprising a combined switching and blocking apparatus ( 30 ), having a switching lever ( 40 ), an operating arrangement ( 60 ), a blocking apparatus ( 70 ) for each fused switch unit ( 10 ), and a locking apparatus ( 80 ).

This application is an application filed under 35 U.S.C. Sec. 371 as anational stage of international application PCT/EP00/07484, which wasfiled Aug. 2, 2000.

TECHNICAL FIELD

The invention relates to a multipole fused switch arrangement for busbarsystems having at least two fused switch units which each holds a fuselink, with the fused switch units having a mounting and contactapparatus for a busbar, and having a switching apparatus for closing andinterrupting the circuit of all the switched fuse units.

BACKGROUND OF THE INVENTION

Such fused switch arrangements are used in particular for protectingthree-phase circuits, in which case three-pole fused switch arrangementsare required.

Since such fused switch arrangements are also operated by those notskilled in the art, it has frequently been found to be a problem thatincorrect operations even on the fused switch arrangement have led todamage to the appliances.

SUMMARY OF THE INVENTION

Accordingly, one object of the invention is to provide a multipole fusedswitch arrangement which is simple to operate and which minimizes therisk of incorrect operations by untrained personnel.

The object is achieved by a multipole fused switch arrangement accordingto the invention.

According to the invention, the fused switch arrangement comprises acombined switching and blocking apparatus.

The combined switching and blocking apparatus has a switching lever,which can be switched to and fro between a switched-on position and aswitched-off position, an operating arrangement for switching switchinglinks of the fused switch units, in which case the operating apparatuscan be switched to and fro between a contact position and an interruptedposition, a blocking apparatus for each fused switch unit for blockingthe operating arrangement in the interrupted position, and a lockingapparatus for locking the fuse link in an operating position, in whichcase the locking apparatus can be switched to and fro between a lockedposition and an isolating position.

The locking apparatus is coupled to the switching lever such that it isalways in the locked position when the switching lever is in theswitched-on position, and which, conversely, is in the isolatingposition when the switching lever is in the switched-off position. Theoperating arrangement is furthermore coupled to the switching lever suchthat it is always in the interrupted position when the switching leveris in its switched-off position. Further coupling between the operatingarrangement and switching lever is possible, but not necessary.

The blocking apparatus blocks the operating arrangement in theinterrupted position when one of the fuse links from the fused switcharrangement is not in its operating position, that is to say it has beencompletely removed from the fused switch arrangement, or has been atleast partially withdrawn from its operating position.

The multipole fused switch arrangement according to the inventioncarries out two major protection functions. Firstly, it prevents thecircuit of the fused switch arrangement from being closed via theswitching links when the fuse links are not all in their operatingposition, and the fused switch arrangement is thus no longer in a readyto operate state. Secondly, it makes it impossible to remove fuse linkswhen the fused switch arrangement is switched on, or to move them fromtheir operating position, without previously having interrupted thecircuit, so that the fuse links can be replaced only when no current isflowing and no voltage is applied. This double protection functionreliably precludes incorrect operations and prevents damage to theelements of the fused switch arrangement, in particular of the contacts,for example as a result of switching arcs and spark flashovers.

In one preferred embodiment, the operating arrangement has a pushrod foreach fused switch unit, with the pushrods being rigidly connected to oneanother and each pushrod resting on spring-loaded switching links viawhich the circuit of the fused switch unit is closed and interrupted.This ensures that all the circuits in all the fused switch units areinterrupted even if only one of the pushrods is blocked in itsinterrupted position, since the associated fuse link is not in itsoperating position.

The operating arrangement can be coupled directly or indirectly to theswitching lever in various ways. The coupling is preferably provided viaa switching rod which is guided in a recess in the switching lever. Theoperating arrangement and the switching lever are coupled on only oneside, that is to say only switching of the switching lever from theswitched-on position to the switched-off position results in force beingexerted on the operating arrangement via the switching rod, while thereis no direct coupling between the switching rod and the operatingarrangement when the switching lever is switched from the switched-offposition to the switched-on position. Thus, although the switching levercan also be moved to the switched-on position when the operatingarrangement is blocked in its interrupted position, no force is exerted,however, by the switching rod or the switching lever on the operatingarrangement. This prevents loading or damage, in particular to theblocking apparatus. At the same time, this ensures that the circuitcannot be closed inadvertently by forceful operation of the switchinglever while at the same time destroying the blocking apparatus.

The operating arrangement is preferably prestressed in its contactposition by at least one spring apparatus, so that the operatingarrangements are automatically located in their contact position when,firstly, all the fuse links are in their operating position and theblocking apparatus is in consequence not acting on the operatingarrangement, and when the operating lever is in its switched-onposition.

Each blocking apparatus is advantageously prestressed by a springapparatus in a position which blocks the operating arrangement in itsinterrupted position, so that the operating arrangement is released onlywhen one fuse link is in its operating position, as a result of whichthe blocking apparatus is moved against the force of the spring effectto a position in which the blocking apparatus and the operatingarrangement do not influence one another. The blocking apparatus isautomatically moved by the spring apparatus to its blocking position assoon as one fuse link is removed from its operating position, although,owing to the locking apparatus, this can occur only if the switchinglever is in its switched-off position, and the operating arrangement isthus in its interrupted position.

When it is in its blocking position, the blocking apparatusadvantageously engages in an opening in the operating arrangement, sothat the blocking apparatus prevents any movement of the operatingarrangement.

Depending on the configuration of the individual fused switch units, thefuse links are inserted directly into the fused switch unit, or fuseplugs are used to hold the fuse links in the fused switch units.

Accordingly, a locking apparatus can be provided which acts directly onthe fuse link, but locking apparatuses are preferably provided which donot act directly on the fuse link, but which engage with a latchingelement on a fuse plug when in their locked position.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the invention will become particularlyclear from the attached schematic drawings, in which:

FIG. 1 shows a cross-sectional view of one embodiment of a three-polefused switch arrangement, with the switching lever being in aswitched-on position and the fused switch arrangement being ready tooperate;

FIG. 2 shows a detail of the fused switch arrangement shown in FIG. 1,with the switching lever being in a switched-off position;

FIG. 3 shows the detail shown in FIG. 2, but with the fuse link havingbeen removed; and

FIG. 4 shows the details shown in FIGS. 2 and 3, but with the switchinglever having been removed to the switched-on position after removal ofthe fuse link.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a fused switch arrangement having three fused switch units10, into each of which a fuse plug 25 with a fuse link 20 is inserted.

Each fused switch unit 10 is mounted on a busbar 90 by means of asurrounding spring 95.

The switching and blocking apparatus according to the inventioncomprises, in the embodiment shown in FIG. 1, a switching lever 40, aspring-loaded switching rod 50, an operating apparatus 60 which in eachcase comprises one pushrod 61 per fused switch unit 10, a spring-loadedblocking apparatus 70, and a likewise spring-loaded locking apparatus80. The spring 52 of the switching rod 50 has a considerably greaterspring constant than the springs 62 in the operating apparatus and thesprings 81 in the locking apparatus, which have approximately the samespring constants. The springs 71 in the blocking apparatus 70 have thelowest spring constant in the switching and blocking apparatus.

When the fused switch arrangement is in the working position shown inFIG. 1, the switching lever 40 is in the switched-on position. Theswitching lever 40 has a recess 41, in which one end of the switchingrod 50 is guided. The other end of the switching rod 50 is seated in abearing 51 in the fused switch arrangement.

The operating arrangement 60 is prestressed in its contact positionindirectly via three springs 62, which are positioned between thehousing of the fused switch arrangement and switching links 12. Theswitching links 12 thus bridge an interruption in a bottom contact 30,which makes contact with a lower contact 21 of the fuse link 20, so thatthe contact is produced between the fuse link 20 and the busbar 90.

The operating arrangement 60 is in this case deflected so far in thedirection of the switching rod 50 that the pushrod 61 on the left in thedrawing rests on the switching rod 50.

Each upper contact 22 of the fuse link 20 makes contact with a tappingcontact 14, so that the circuit is closed via the tapping contact 14,the upper contact 22 and the lower contact 21 of the fuse link 20, thebottom contact 13, the switching link 12, the extension of theinterrupted bottom contact 13 and the busbar 19.

The fuse link 20 is always pressed by force from a spring 26 in the fuseplug 25 against the bottom contact 13, thus ensuring a reliable contact.

The locking apparatus is pressed by the formed-out region 43 of theswitching lever 40 into an opening (which is used as a latching element27) in the fuse plug 25, so that the fuse plug 25 is fixed, togetherwith the fuse link 20, in its operating position. The locking apparatus80 is formed as one part for all the fused switch units and isprestressed by means of a spring apparatus 81 against the formed-outregion 43 of the switching lever 40.

Individual fused switch units and their assemblies are identical, and itshould once again be mentioned that both the locking apparatus 80 andthe operating arrangement 60 are formed as one part for all the fusedswitch units, so that the individual elements can thus move onlytogether, and no relative movement is possible, for example between thepushrod 61. In contrast, the blocking apparatuses 70 are autonomousassemblies, which are separate from one another, in each fused switchunit 10.

The method of operation of the switching and blocking apparatus 30according to the invention is clear from the further FIGS. 2 to 4,which, for simplicity, show only a detail of the embodiments.

In FIG. 2, the switching lever 40 has been moved from its switched-onposition to its switched-off position. The locking apparatus 80, whichis prestressed against the switching lever 40 by means of the spring 81,has been moved to the left in the figure, after passing over a step 44(which is introduced in the switching lever 40) in the switching lever40, so that the interlocking element 82 no longer engages with theopening 27 in the fuse plug 25. The fuse plug 25, together with the fuselink 20, is thus no longer locked in its operating position.

The switching of the switching lever 40 to its switched-off positionresults in the switching rod 50 pivoting to the right in its bearing 51and in the recess 42, as a result of which the operating arrangement 60is forced via the pushrod 61 to its interrupted position, in which theswitching link 12 is lifted off the bottom contact 13. The circuit isthus interrupted at the bottom contact 13.

Since the fuse plug 25 is still in its operating position and pressesagainst a protrusion on the blocking apparatus, the blocking apparatus70 is still held in a non-blocking position against the influence of itsspring apparatus 71.

Subject to the precondition that all the other fused switch units (whichare not shown in FIG. 2), are in analogous positions, the switchinglever 40 can be moved back to its switched-on position, as a result ofwhich the fuse plugs 25 are automatically locked by the lockingapparatus 80. Since the operating arrangement 60 is not blocked, it ispushed to the left in the drawing together with the switching link 12 bymeans of the spring apparatus 62, as a result of which the switchinglink 12 makes contact with the interrupted bottom contact 13, and closesthe circuit.

FIG. 3 shows the fused switch arrangement shown in FIG. 2, but with thefuse plug 25 together with the fuse link 20 having been removed from thefused switch unit 10. In order to remove the fuse plug 25 from the fusedswitch unit, it must be pushed slightly to the left in the figure, inorder that the latching element 16 of the fuse plug 25 can be moved overthe projection 15 of the housing of the fused switch arrangement.

The locking apparatus 80 is, as already explained in conjunction withFIG. 2, no longer engaged with the fuse plug 25, so that the lockingapparatus 80 does not prevent removal of the fuse plug 25 and of thefuse link 20.

Once the fuse plug 25 is no longer pressing downwards onto theprotrusion on the blocking element 70, the blocking apparatus 70 ismoved upwards in the drawing by means of its spring 71, so that parts ofthe blocking apparatus 70 extend into an opening 63 in the pushrod 61 ofthe operating arrangement 60, blocking it.

As is shown in FIG. 4, although the switching lever 40 can be moved toits switched-on position, this results, however, in the switching rod 50also being pivoted to the switched-on position. The pushrod 61 and themounting arrangement 60 do not follow the movement of the switching rod50 since the blocking apparatus 70 is engaged in the opening 63 in thepushrod 61. Since the switching rod 50 and the pushrod 61 are not firmlyconnected to one another, movement of the switching lever does not exertany force on the pushrod 61 or on the blocking apparatus 70, either. Thepushrod 61 and the blocking apparatus 60 are still blocked, so that theswitching link 12 is also held at a distance from the bottom contact 13,against the spring force of the spring 62, by the pushrod 61. Thus, asdesigned, the circuit is still interrupted, as before.

Merely for the sake of completeness, it should be noted that theintegral, rigid operating arrangement 60 means that the switching links12 of the other fused switch units 10 are also held by the correspondingpushrods 61 at a distance from the associated bottom contact 13, even ifthe fuse plug 25 has not been removed from these fused switch units 10and the corresponding pushrod 61 is in consequence not autonomouslyblocked by the separate blocking apparatus 70.

Since the switching rod 50 and the pushrod 61 are not firmly connectedto one another this prevents careless operating personnel from beingable to cause damage to the fused switch arrangement when the operatingarrangement 60 is blocked by one of the blocking apparatuses 70.

Finally, it should be mentioned that, of course, modifications can becarried out to the specific refinements of this embodiment withoutdeparting from the subject matter of the invention. In particular, fuselinks without fuse plugs can be inserted directly into the fused switchunits, and different types of fuse, for example screw-in fuses, may beused instead of plug-in fuses, or a different refinement of theswitching lever or of the recess with the dead point may be chosen forswitching which is essentially; independent of manual switching.

Furthermore, it should be mentioned that the drawings are only schematicand, in particular, no restrictions with regard to dimensions and sizescan be derived from the drawings.

1. A multipole fused switch arrangement for busbar systems having atleast two fused switch units (10) which each holds a fuse link (20),with the fused switch units (10) having a mounting and contact apparatus(11) for a busbar (90), and having a switching apparatus for closing andinterrupting the circuit of all the switched fuse units (10), whereinthe fused switch arrangement comprises a combined switching and blockingapparatus (30), having a switching lever (40) which can be switched toand fro between a switched-on position and a switched-off position, anoperating arrangement (60) for switching switching links (12) in thefused switch unit (10), in which case the operating arrangement (60) canswitch to and fro between a contact position and an interruptedposition, in each case one blocking apparatus (70) for each fused switchunit (10) for blocking the operating arrangement (60) in the interruptedposition, and a locking apparatus (80) for locking the fuse links (20)in an operating position, in which case the locking apparatus (80) canbe switched to and fro between a locked position and an isolatingposition, with the locking apparatus (80) being coupled to the switchinglever (40) such that it is in the locked position when the switchinglever (40) is in the switched-on position, and is in the isolatingposition when the switching lever (40) is in the switched-off position,with the operating arrangement (60) being coupled to the switching lever(40) such that it is in the interrupted position when the switchinglever (40) is in the switched-off position, and with a blockingapparatus (70) blocking the operating arrangement (60) in theinterrupted position when one of the fuse links (20) of the associatedfused switch arrangement is not in its operating position.
 2. The fusedswitch arrangement as claimed in claim 1, wherein the operatingarrangement (60) has a pushrod (61) for each fused switch unit (10),with the pushrods (61) being rigidly connected to one another.
 3. Thefused switch arrangement as claimed in claim 2, wherein each pushrod(61) rests on the spring-loaded switching links (12).
 4. The fusedswitch arrangement as claimed in claim 1, wherein the operatingarrangement (60) is coupled to the switching lever (40) via a switchingrod (50).
 5. The fused switch arrangement as claimed in claim 4, whereinthe switching rod (50) is guided in a recess (41) in the switching lever(40).
 6. The fused switch arrangement as claimed in claim 5, wherein therecess (41) has a dead point (42) for switching which is essentiallyindependent of manual switching.
 7. The fused switch arrangement asclaimed in claim 1, wherein the coupling between the operatingarrangement (60) and the switching lever (50) is on one side, and onlyswitching of the switching lever (40) from the switched-on position tothe switched-off position results in force being exerted on theoperating arrangement (60) in the direction of the interrupted position.8. The fused switch arrangement as claimed in claim 1, wherein theoperating arrangement (60) is prestressed by at least one springapparatus (62) in its contact position.
 9. The fused switch arrangementas claimed in claim 1, wherein each blocking apparatus (70) isprestressed by a spring apparatus (71) in a position which blocks theoperating arrangement (60) in its interrupted position.
 10. The fusedswitch arrangement as claimed in claim 9, wherein each blockingapparatus (70) is arranged such that the movement of the associated fuselink (20) to its operating position forces said blocking apparatus (70)against the spring force of the spring apparatus (71) to a positionwhich releases the operating apparatus (60).
 11. The fused switchedarrangement as claimed in claim 1, wherein, in its blocking position,the blocking apparatus (70) engages in an opening (63) in the operatingarrangement (60).
 12. The fused switch arrangement as claimed in claim1, wherein the locking apparatus (80) locks the fuse link (20) directly.13. The fused switch arrangement as claimed in claim 1, wherein thelocking apparatus (80) locks the fuse link (20) indirectly via a fuseplug (25), in which the fuse link (20) is inserted.
 14. The fused switcharrangement as claimed in claim 13, wherein the locking apparatus (80)has an interlocking element (82) which, in the interlocked position,engages in a interlocking manner in a latching element (27) on the fuseplug (25).